Electric oven



June 18, 1929. 5, HE|$E 1,717,605

ELECTRIC OVEN Filed July 8. 1926 5 Sheets-Sheet l June 18, 1929. R 5 HEISE 1,717,605

ELECTRI C OVEN Filed July 1926 5 Sheets-Sheet 2 -7 29. 5.9 H A7 55 r 7 June 18, 1929. HE|SE 1,717,605

ELECTRIC OVEN Filed July 8. 1926 5 Sheets-Sheet 5 R. S. HEISE ELECTRIC OVEN June 18, 1929.

Filed July 1926 5 Sheets-Sheet 4 June 18, 1929. R. s. HEISE 1.717.605

ELECTRIC OVEN Filed July 8. 1926 5 Sheets-Sheet 5 Patented June 18, 1929.

UNITED STATES ROSCOE S. HEISE, OF MIDDLETOWN, OHIO.

ELECTRIC OVEN.

Application filed July 8, 1926.

This invention relates to electric ovens, stoves and the like, and is fully described in the following specification and shown in the accompanying drawings, 'in which:

- Figure 1 is a front elevation of an electric oven embodying the invention;

Fig. 2 is a side elevation of the same showing the side wall partly broken away and showing the door carrying mechanism in closed position;

Fig. 3 is a similar view of the same showing; in fulllineposition, the door withdrawn from the oven in dotted line position, the door lowered;

Fig. 4, is an enlarged vertical section on the line 44 of Fig. -1; and

Fig. 5 is a transverse section on the line 55 of Fig. 4.

The embodiment illustrated comprises an oven having ahollow sheet metal rear wall 10, side walls 11 and 12, bottom 13 and top 14 secured together as by means of screws 15 and 16 and supported upon legs 17.

A sheet metal front .18 is secured therein and has a large rectangular opening which is surrounded by the door frame 19 preferably of cast iron which is secured to the front plate 18.

Theoven proper 20 'is made up of an oven bak21 a front 'flange22 and a center portion 23, whichare secured together'by lapped joints as shown in'Eig. 4. The center .portion 23 is also refera'bly made up of four pieces; name- 1y, si emembers24 and top and bottom members 2 5 and 26 respectively which are likewise secured together by means of lapped joints '27 and 28. The one-piece flange 22 is enlarged at22 toreceive the door as will later boeir-plained and terminates in an outwardly extending flange 22 which is securely held hetween .the'door frame1'9 and the front plate 18, as by means of screws or rivets, not shown.

rOmit'ting 'for the present the mechanism for carrying thedoor, it consists essentially of a front door plate 29 and a pressed metal plate 30having a flange 30 by which it is secured to the front door plate 30 by means of screws 3l.

Within the door is a series of castings 32, each of which occupies substantially onefourth of the space and these are provided with ribs 33 which are screw-threaded as shown in Fig. 4 to receive the conical nut 34 which serves to expand them out against the metal 30 forming the edge of the threaded hub 35.. Thus an adjustment is provided Serial No. 121,145.

which permits the operating lever 37 to be set so that it will extend at any angle which the operator desires. It is preferably so made however that it will stand in the vertical position shown in Fig. 3 when the 'door is unlocked so as to be released and is preferably held in this position by means of balls 40 on the spring 41.

Thus it will be seen that when the door is forced in to the position shown in F i 4, the operator turns the lever 37 forcing the castings 32 outwardly thereby firmly gripping the sheet metal members 30 and 22" between the castings 32 and the door frame 19. Keys 42 are placed between the castings 32 and lie flush with the same so that pressure is exerted substantially uniform upon the adjacent metal members 22 and 30".

Ears 43 and 44 are'secured at .each side of the door. The car 44 is pivotally secured at 45 to the end of the Z-bar 46 which is pivotally suspended at 47 and 48 on parallel links 50 and 51. The ends of these links in turn are pairs of parallel links 52, 53 and 54, .55. The links of each of these pairs are substantially the same and their pivot points are so located so as to keep membersof each pair of links parallel at all times.

The ear 43 is pivotally connected to a rod 5'6 which is pivotally connected to the upper end of a lever 57 which is pivotally connected at 58 to the Z-bar 46. The lever 57 carries a plate '59 to which is pivotally connected a rod 60 at the point :61, this rod passing through an opening 62 in the bottom plate 13 and carrying a washer 63 which compresses a spring 64 which is mounted on the rod 60.

Thus it will be seen that when the door is pulled outwardlyfrom the'closed position of Fig. 2, to the open position .of Fig. 3., the rod 56 and lever 57 do not move with respect to the Z-bar 46, but the whole is carried outwa rdly by the parallel link motion previously described. A comparison of the positions of these links in Figs. 2 and 3 will make this clear, and it will also be observed that the opening 62 is so placed that the spring 64 assists in closing the door as shown in Fig. 2 when it has gone in 'a predetermined amount and it likewise assists in forcing the door outwardly when the door has been moved out beyond the dead center as shown in Fig. 3.

It will be understood, of course, that the system of links and levers previously described and shown in Figs. 2 and 3 is duplicated on the opposite side of the oven lining.

Having drawn the door outwardly to the position shown in Fig. 3 by this straight line mechanism, the operator continues to move the door outwardly as by pulling on the lever 37 which now swings the door about the pivots 45 at each side. The link 52 has an extension 52 which extends across to the opposite side and this serves to keep the links of the two sides in about the same relative positions at all times so that any force maintained to open and close the door if exerted at one side of the center of the door will be transmitted from the mechanism of one side to that of the other so as to prevent one side of the door moving in or out in advance of the other.

As the door swings down about the pivots 45 the rods 56 are drawn from the full line position to the dotted line position of Fig. 3 when the door now assumes a horizontal position with the now horizontal surface of the door substantially on a level with the bottom of the line of the oven so that cooking utensils or the like in the oven may be readily drawn out on the horizontal surface of the door. To accomplish this the rods 56 are pivotally connected as has been previously stated, to levers 57 which in turn are pivotally connected to the Z-bars 46. As the door is swung down the rods 56 cause the levers 57 and plates 59 to swing to an angle of 90 from the full line position to the dotted line position in Fig. 3. Thus the rod 60 by this movement again passes through dead center so that the springs 64 serve to maintain the door in both the raised and lowered position.

For the convenience of the operator a thermometer 65 of any suitable type is se cured in the door and extends through it so as to be visible in front of the oven. On the front of the oven are also three controlling switches 66 which serve to control the amount of current passing through the heating elements of which there are three, one, 67 being placed in the top of the oven, one 68 in the bottom of the oven and the other 69 on the top of the casing. These heating elements are not shown in detail as they are well known in the art, nor have I shown the connections between these heating elements and the source of current supply.

The door closing mechanism is so nearly airtight that a relief valve 70 is required and this is inserted in the back as shown in Fig. 4. This is a spring operated device which is so made as to permit a small excess of pressure about atmospheric to escape out- \vardly therethrough and likewise when a vacuum within the oven chamber occurs during the time when it is cooling ofi, air will be permitted to enter through this same relief valve.

The sides 30 of the door are preferably tapered slightly as is also the flange 22* so as to permit the door to be opened and closed more easily. A depression 22" around the flange 22* catches any moistui'e which collects on the walls.

Attention is particularly drawn to the construction of the chamber in which the longitudinal seams 27 and 28 are headed into the two parallel transverse beads 27 and 27*.

In operation, the vessel containing the material to be cc: d is placed in the oven, preferably on racks, not shown, and electric current is turned on by means of the switches 68 and left on a predetermined degree of heat when the electric current is shut off. Cools ing then proceeds on the contained heat. To assist in retaining this heat, any suitable insulation such as mineral wool (not shown) may be interposed between the oven proper 2i and the outer shell 10.

While I have shown and described but a single embodiment of this invention, it is to be understood that it is capable of many modifications. Changes therefore in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

I. In an electric oven, an oven chamber closed except for an opening at one vertical side, a door adapted to close said opening, and mechanism for carrying saiddoor into said opening parallel to itself, said mechanism being movable to lower said door from a vertical position to a substantially horizontal position and to maintain it in either of these positions.

2. In an electric oven, an oven chamber closed except for an opening at one vertical side, a door adapted to close said opening, and mechanism for carrying said door into said opening parallel to itself, said mechanism being movable to lower said door from a vertical position to a substantially horizontal position on a level with the bottom of the oven chamber and to maintain it in either of these positions.

3. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, and mechanism for carrying said door into said opening parallel to itself, said mechanism being movable to lower said door to a substantially horizontal position, said mechanism comprising means for forcing said door toward an open or a closed position when it has passed a predetermined point.

4. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, and a sys tem of parallel links for carrying said door into said opening parallel to itself, said system of parallel links being movable to lower said door to a substantially horizontal position.

5. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, and a system of parallel links at each side of the oven, the links at the two sides being operativcly connected together for carrying said door into said opening parallel to itself, said system of parallel links being movable to lower said door to a substantially horizontal position.

6. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, said door having a sheet metal cover and means in said door for expanding said cover out- Wardly into engagement with said opening.

7. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, said door having a sheet metal cover means for carry ing said door, and means in said door for expanding said cover outwardly into engagement with said opening.

8. In an electric oven, an oven chamber closed except for an opening at one side. a door adapted to close said opening, a reinforcing member surrounding said opening, said door having a sheet metal cover, expansible members within said door for pressing said cover into engagement with said opening, and means for forcing said expansible members outwardly to lock and seal said door.

9. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, a reinforcing member surrounding said opening, said door having a sheet metal cover, expansible members within said door for pressing said cover into engagement with said opening, and a tapered screw having a handle extending outside said door for forcing said expansible members outwardly to lock said door.

10. In an electric oven, an oven chamber closed except for an opening at one side, a door adapted to close said opening, a reinforcing member surrounding said opening, said door having a sheet metal cover, expansible members within said door for pressing said cover into engagement with said opening, and a tapered screw having a handle extending outside said door for forcing said expansible members outwardly to lock said door, said handle being adjustable so as to be set at any desired angle.

11. In an electric oven, an oven chamber having a sheet metal lining closed except for an opening at one side, a door adapted to close said opening, said door having a sheet metal cover adapted to fit the opening in said lining, and means for expanding said sheet metal cover into contact with said sheet metal lining to lock and seal the same.

ROSCOE S. HEISE. 

